today both governor romney and president obama will head to ohio a key battleground state to the campaign. now, where 18 electoral votes are up for grabs, with the election just a month a with now this is going to be very important because ohio is a state that some people believe could make or break victory. cate caugiran, cbs 5. >>> big bird is the star of a new ad for president obama. >> it's me, big bird. >> big, yellow, a menace to our economy. mitt romney knows it's not wall street... >> the obama campaign released this ad just this morning and it pokes more fun at homicide's pledge to cut funding for public television. a pew research survey three weeks ago gave president obama an 8-point lead among likely voters. now romney has taken a 4-point lead in an updated survey. he is excited about his chances of winning next month. >> people wonder why it is i'm so confident we're going to win. i'm confident because i see you here on a day like this. this is unbelievable, thank you so much. >> he campaigned in the pouring rain in virginia yesterday after giving a speech blasting president o